September 6th, though Paramount themsleves have not announced a date yet.
ebay.co.uk have a 'Region 2' dvdr set for £17delivered:-
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&category=41589&item=6406191072&rd=1&ssPageName=WDVW
I loved DS9 and thought the series got stronger (season 6 being my personal fave) as it progressed - it's tributes to TOS are many and very well done.
Trek lost out when TIIC stayed with Berman and discounted the qualities of Moore and the other DS9 execs - seemingly more so now that Morre's done such a promising start on the new Galactica series, and Trek had now gone into a much needed hibernation. Recycled stories and direction that havn't differed from the days of the TNG crew has not paid off during VOY and ENT, and it will not in the future, massive changes are needed for quality Trek for the future...